Nitrogen Removal by River Systems of the Feng River Basin in China

2014 ◽  
Vol 1015 ◽  
pp. 631-634
Author(s):  
Jian Hui Zhi ◽  
Ai Zhong Ding ◽  
Shu Rong Zhang
Keyword(s):  
Water System ◽  
River System ◽  
Dry Season ◽  
River Network ◽  
Nitrogen Loading ◽  
Combined Processes ◽  
River Systems ◽  
N Removal ◽  
N Input ◽  
The Impact

As human activities continue to alter the global nitrogen cycle, the ability to predict the impact of increased nitrogen loading to river systems is becoming more and more important. Nitrogen retention is of particular interest because it is through its combined processes that local and downstream nitrogen concentrations are reduced. To determine the potential for N removed from Feng River network, we used stream chemistry and hydrogeo-morphology data from 17 stream and river sites to estimate NO3-–N removal in Feng River system of China. We used a N removal model to predict NO3-–N input and removal in December of 2011. NO3-–N input ranged from 0.06 to 20 kg km-1d-1in the Feng River system. Cumulative river network NO3-–N input was 446 ton year-1 in dry season in whole water system. NO3–N removal based on the model ranged from 0.04 to 4.2 kg km-1d-1 December of 2011 for Feng River. Cumulative river network NO3-–N removal predicted by the model was 58 ton year-1 in dry season. Proportional NO3–N removal (PNR) ranged from 0.2 to 0.6 in this time. PNR was negatively correlated with both stream orders.

scholarly journals ĐẶC ĐIỂM HỆ THỐNG SÔNG CỔ VÀ TÁC ĐỘNG NHÂN SINH DỰA TRÊN KẾT QUẢ MÔ HÌNH TIẾN HÓA TỈ LỆ LỚN KHU VỰC CHÂU THỔ SÔNG HỒNG

2020 ◽  
Vol 19 (4) ◽  
pp. 463-478
Author(s):  
Mai Duc Dong ◽  
Phung Van Phach ◽  
Nguyen Trung Thanh ◽  
Duong Quoc Hung ◽  
Pham Quoc Hiep ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
River System ◽  
River Network ◽  
River Delta ◽  
Red River ◽  
River Systems ◽  
Red River Delta ◽  
The World ◽  
History Of

The Simclast model has been verified and applied effectively in simulating the delta development for some major deltas in the world. In this study, we applied the model Simclast for simulating the history of the Red river delta development in late Pleistocene-Holocene. Results of the model reveal that the mainland of study area had reduced rapidly during transgression period (10,000-8,000 BP). The morphology changed significantly in the paleo-Red and Day river systems, but slightly in the paleo Thai Binh river system. The paleo-river network had been active in upper part before 11,000 BP and then shifted seaward until 2,000 BP. The river-sea interaction causes erosion and accumulation; as a result the morphology changed remarkably. The paleo-Thai Binh river had been inactive until 5,500 BP and then it was active but the morphology had not varied remarkably. The recent coastline generated from Simclast is relatively in accordance with the present coastline.

scholarly journals Seasonal Variation of Phthalate Esters in Urban River Sediments: A Case Study of Fengshan River System in Taiwan

2021 ◽  
Vol 14 (1) ◽  
pp. 347
Author(s):  
Kuan-Nan Lin ◽  
Chiu-Wen Chen ◽  
Chih-Feng Chen ◽  
Yee Cheng Lim ◽  
Chih-Ming Kao ◽  
...  
Keyword(s):  
Phthalate Esters ◽  
River Sediments ◽  
Aquatic Organisms ◽  
River System ◽  
Dry Season ◽  
Ecological Risks ◽  
Total Risk ◽  
Wet Season ◽  
Potential Risks ◽  
The Impact

The Fengshan River system is one of the major rivers in Kaohsiung City, Taiwan. This study investigated the concentration of eight phthalate esters (PAEs) in sediments of the river and the impact of potential ecological risks during the dry and wet seasons. The potential risk assessment of sediment PAEs was evaluated by adopting the total risk quotient (TRQ) method. The total PAEs concentrations (∑PAEs) in the sediments of the Fengshan River system are between 490–40,190 ng/g dw, with an average of 8418 ± 11,812 ng/g dw. Diisononyl phthalate (38.1%), bis(2-ethylhexyl) phthalate (36.9%) and di-isodecyl phthalate (24.3%) accounted for more than 99.3% of ∑PAEs. The concentration of ∑PAEs in sediments at the river channel stations is higher during the wet season (616–15,281 ng/g dw) than that during the dry season (490–1535 ng/g dw). However, in the downstream and estuary stations, the wet season (3975–6768 ng/g dw) is lower than the dry season (20,216–40,190 ng/g dw). The PAEs in sediments of the Fengshan River may have low to moderate potential risks to aquatic organisms. The TQR of PAEs in sediments at the downstream and estuary (TQR = 0.13) is higher than that in the upstream (TQR = 0.04). In addition, during the wet season, rainfall transported a large amount of land-sourced PAEs to rivers, leading to increased PAEs concentration and potential ecological risks in the upper reaches of the river.

Factors controlling primary productivity in a wet–dry tropical river

2013 ◽  
Vol 64 (7) ◽  
pp. 585 ◽  
Author(s):  
S. J. Faggotter ◽  
I. T. Webster ◽  
M. A. Burford
Keyword(s):  
Algal Blooms ◽  
Algal Biomass ◽  
Arid Zone ◽  
River System ◽  
Dry Season ◽  
Trophic Levels ◽  
Nutrient Inputs ◽  
Tropical River ◽  
Algal Production ◽  
The Impact

Algal production in rivers fuels foodwebs, and factors controlling this production ultimately affect food availability. Conversely, excessive algal production can have negative effects on higher trophic levels. The present study examined permanent waterholes in a disconnected wet–dry tropical river to determine the controls on algal production. Primary production in this river system was high compared with arid-zone and perennially flowing tropical rivers. Phytoplankton biomass increased over the dry season but this appeared to be because waterhole volume decreased, due to evaporation. Nitrogen (N) was the key limiting nutrient for phytoplankton, with rapid N turnover times, depletion of particulate 15N-nitrogen reflecting increasing N fixationover the dry season, and N stimulation in phytoplankton bioassays. The waterholes were shallow, providing sufficient light for accumulation of benthic algal biomass. Exclosure experiments were also conducted to determine the impact of top–down control on benthic algal biomass, with no evidence that exclusion of fish and crustaceans increased benthic algal biomass. The shallow off-channel waterhole in our study had substantially higher concentrations of nutrients and chlorophyll a than did the on-channel waterholes. This suggests that future anthropogenic changes, such as increased water extraction and increased nutrient inputs, could make the waterholes more vulnerable to deteriorating water quality, such as e.g. algal blooms, low concentrations of dissolved oxygen.

Modelling impacts of pollution in river systems: a new dispersion model and a case study of mine discharges in the Abrud, Aries and Mures River System in Transylvania, Romania

2009 ◽  
Vol 40 (2-3) ◽  
pp. 306-322 ◽  
Author(s):  
S. C. Chapra ◽  
P. G. Whitehead
Keyword(s):  
River Flow ◽  
Dispersion Model ◽  
River System ◽  
Order Kinetic ◽  
River Systems ◽  
Water Release ◽  
Pollution Levels ◽  
Key Sites ◽  
The Impact

A new model of dispersion has been developed to simulate the impact of pollutant discharges on river systems. The model accounts for the main dispersion processes operating in rivers as well as the dilution from incoming tributaries and first-order kinetic decay processes. The model is dynamic and simulates the hourly behaviour of river flow and pollutants along river systems. The model has been applied to the Aries and Mures River System in Romania and has been used to assess the impacts of potential dam releases from the Roşia Montană Mine in Transylvania, Romania. The question of mine water release is investigated under a range of scenarios. The impacts on pollution levels downstream at key sites and at the border with Hungary are investigated.

scholarly journals A New Multibranch Model for Metals in River Systems: Impacts and Control of Tannery Wastes in Bangladesh

2021 ◽  
Vol 13 (6) ◽  
pp. 3556
Author(s):  
P. G. Whitehead ◽  
Z. Mimouni ◽  
D. Butterfield ◽  
G. Bussi ◽  
M. A. Hossain ◽  
...  
Keyword(s):  
Acid Rock Drainage ◽  
Treatment Plant ◽  
River System ◽  
Point Sources ◽  
Effluent Treatment ◽  
River Systems ◽  
Acid Rock ◽  
Pollution Levels ◽  
Copper Zinc ◽  
The Impact

A new multibranch Integrated Catchment (INCA) model INCA-Metals has been developed to simulate the impact of tannery discharges on river systems. The model accounts for the key chemical reaction kinetic processes operating as well as sedimentation, resuspension, dilution, mixing and redistribution of pollutants in rivers downstream of tannery discharge points and for mine discharges or acid rock drainage sites. The model is dynamic and simulates the daily behaviour of hydrology and eight metals, including cadmium, mercury, copper, zinc, lead, arsenic, manganese and chromium, as well as cyanide and ammonia. The model is semi-distributed and can simulate catchments, tributaries and instream river behaviour. The model can also account for diffuse pollution from rural runoff as well as point sources from effluent and trade discharges. The model has been applied to the new Savar tannery complex on the Dhaleshwari River system in Bangladesh to assess the impacts on pollution levels in the river system and to evaluate a set of treatment scenarios for pollution control, particularly in the dry season. It is shown that the new effluent treatment plant at Savar needs to significantly improve its operation and treatment capability in order to alleviate metal pollution in the downstream Dhaleshwari River System and also protect the Meghna River System that falls in the Bay of Bengal.

Numerical Study on the Affection of River System of Different Areas to Thermal Environment of Residential Neighborhood

2012 ◽  
Vol 433-440 ◽  
pp. 1422-1427
Author(s):  
Pei Hong Zhang ◽  
Xin Chun Zhang ◽  
Zhong Jiao Ma ◽  
Jia Lin Song
Keyword(s):  
Mathematical Model ◽  
Temperature Field ◽  
Relative Humidity ◽  
Thermal Environment ◽  
Numerical Study ◽  
Water System ◽  
River System ◽  
River Systems ◽  
Residential Neighborhood ◽  
Simulation Results

Based on software of Airpak, a mathematical model of a residential neighborhood in Shenyang was built to analyze the thermal environment of the area in summer. Different areas of river system, saying, original and double area, were located in south of the residential neighborhood. A series of results at pedestrian level of 1.5 meters were obtained, such as temperature field, relative humidity(RH) field, Predicted Mean Vote and Predicted Percent Dissatisfied(PMV-PPD), as well as Mean Age of Air(MAA). The simulation results showed that the affect to the thermal environment of the residence were different when the area of river systems was different. All the simulation results illustrated that the thermal environment was better if the area of water system was increased.

scholarly journals Nitrogen removal by denitrification and annamox processes in freshwater rivers of high nitrogen loading region of China

2017 ◽  
Vol 19 (4) ◽  
pp. 650-657 ◽  
Keyword(s):  
River System ◽  
Nitrogen Loading ◽  
Ammonium Oxidation ◽  
Total N ◽  
Membrane Inlet Mass Spectrometry ◽  
Relative Contribution ◽  
N Removal ◽  
The Mean ◽  
High Nitrogen Loading

The importance of anaerobic ammonium oxidation (anammox) – a metabolic pathway that can generate dinitrogen – remains poorly understood in freshwater river system. Using the 15N-isotope pairing technique (15N IPT) combined with membrane inlet mass spectrometry (MIMS), the potential rates of denitrification, anammox and total N removal, and their respective contributions to total N2 production were evaluated in 11 rivers in the Taihu Lake region of China. The measured potential rates of denitrification, total N removal and anammox varied from 18.9±0.3 to 70.0±11.4, 26.3±0.4 to 71.3±11.1 and 1.3±0.3 to 11.0±2.5 μmol N m-2 h-1, respectively. The relative contribution of anammox to total N2 production (ra%) ranged from 2.0±0.8% to 29.9±0.7%. The mean potential denitrification and the total N removal rates varied spatially in these 11 rivers, with the highest rates occurring in the western rivers of the region, while the mean potential anammox rates and ra% displayed the opposite trend with the highest values occurring in the southern rivers of the region. The contents of nitrate and dissolved organic carbon in sediments appeared to be the primary controlling factors for denitrification and anammox in these studied rivers. Our results indicated that the potential rates of N removal varied spatially, and denitrification is the dominant activity for removing fixed N but the role of anammox is not negligible in freshwater rivers.

scholarly journals The diet of otters (Lutra lutra) on the Agri river system, one of the most important presence sites in Italy: a molecular approach

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9606 ◽  
Author(s):  
Maria Buglione ◽  
Simona Petrelli ◽  
Claudia Troiano ◽  
Tommaso Notomista ◽  
Eleonora Rivieccio ◽  
...  
Keyword(s):  
High Throughput Sequencing ◽  
Management Strategies ◽  
Water System ◽  
Taxonomic Status ◽  
River System ◽  
Predatory Behavior ◽  
Lutra Lutra ◽  
Management Actions ◽  
Wide Range ◽  
The Impact

Background The Eurasian otter (Lutra lutra) underwent a strong decline in large areas of the Central-Western part of its distribution range, during the second half of the twentieth century. In Italy, only residual fragmented nuclei survive in the Central-Southern part of the peninsula. Nowadays, the otter is one of the most endangered mammals in Italy, and increasing the knowledge about the ecology of this species is a key step in defining fitting management strategies. Here we provide information about the diet of otter on the Agri river system, one of the most important presence sites in Italy, to understand both the species’ food requirements and the impact on fish communities. Methods DNA metabarcoding and High Throughput Sequencing were used on DNA extracted from spraints. We amplified DNA with a primer set for vertebrates, focusing efforts on the bulk of the otter’s diet (fishes and amphibians). Results Our findings showed that the diet of the otter was dominated by cyprinids (97.77%, and 99.14% of fishes), while amphibians represented 0.85% of the sequences analyzed. Results are in general accordance with previous studies based on morphological characterization; however, molecular analyses allow the resolving of some morphological uncertainties. Although the study area offers a very wide range of available prey, the diet of the otters shows marked selectivity. We highlighted a variation in prey consumed, in accordance with the typology of water system (i.e., river, lake, tributary). Some of the preys found in the diet were alien species introduced by man for sport fishing. Our findings could help define strategies useful for the conservation of the otter population in Southern Italy, suggesting management actions directed at avoiding fish community alterations through illegal stockings without severe controls on their taxonomic status. These introductions could result in a general reduction in the diversity of the otter’s preys, affecting its predatory behavior.

Decline and regional extirpation of freshwater mussels (Unionidae) in a small river system invaded by Dreissena polymorpha: the Rideau River, 1993–2000

2001 ◽  
Vol 79 (12) ◽  
pp. 2181-2191 ◽  
Author(s):  
André L Martel ◽  
Diane A Pathy ◽  
Jacqueline B Madill ◽  
Claude B Renaud ◽  
Stuart L Dean ◽  
...  
Keyword(s):  
Dreissena Polymorpha ◽  
Freshwater Mussels ◽  
Ecological Impact ◽  
Benthic Fauna ◽  
River System ◽  
Small River ◽  
River Systems ◽  
Long Term Study ◽  
The Impact ◽  
Rideau River

Data pertaining to the ecological impact of the exotic zebra mussel, Dreissena polymorpha, on benthic fauna in small river systems are scarce. We conducted a long-term study to assess the impacts of the D. polymorpha invasion in a small river system (100 km) in eastern Ontario during an 8-year period (1993–2000). A 30-km downstream section of the Rideau River was studied before and during rapid population growth of D. polymorpha in the area. During 1993–1995, D. polymorpha abundance on hard substrates increased by four to six orders of magnitude and remained high thereafter. A comparable temporal pattern of D. polymorpha abundance was observed on shells of live freshwater mussels (Unionidae). During peak fouling (1995–1997), mass ratios (mass of attached D. polymorpha / mass of live unionid host) ranged from 0.37 to 1.81. SCUBA-diving surveys (50-m transects) were conducted to examine the impact of D. polymorpha on native unionids in impounded river habitats. In 1993–1994, three unionid taxa were commonly found in 10-m2 quadrats sampled along transects: Elliptio complanata, Pyganodon grandis, and Lampsilis radiata. Overall, the mean density of unionids declined 5- to 8-fold from 1993 to 1997, coinciding with a rapid increase in D. polymorpha densities on unionids. By 1997, i.e., 4 years after fouling began, P. grandis and L. radiata had been extirpated from those sites, with only E. complanata remaining. By 2000, i.e., 7 years after fouling began, all three unionid taxa had been essentially extirpated from the 30-km section of the river, with only one live individual (E. complanata) collected during 10 extensive diving surveys (the total estimated area of riverbed surveyed was 4000 m2). This study indicates that heavy fouling by D. polymorpha causes the extirpation of unionids in small impounded river systems ([Formula: see text]100 km).

The impact of socioeconomic system on the river system in a heavily disturbed basin

2019 ◽  
Vol 660 ◽  
pp. 851-864 ◽  
Author(s):  
Zengliang Luo ◽  
Qiting Zuo ◽  
Quanxi Shao ◽  
Xiangyi Ding
Keyword(s):  
River System ◽  
Socioeconomic System ◽  
The Impact
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